1. Field of the Invention
The present invention relates to a liquid crystal display panel and a liquid crystal display device using the liquid crystal display panel.
2. Description of the Related Art
A liquid crystal display panel includes two glass panels, between which a liquid crystal is sandwiched and on each of which a plurality of transparent electrodes (or wirings) are arranged in order. In a liquid crystal display device, a printed circuit board, on which a plurality of semiconductor integrated circuit (IC) chips and the like for driving the liquid crystal display panel are mounted, is arranged around the panel. The transparent wirings of the liquid crystal display panel are applied with the driving voltages generated by the semiconductor IC chips, thus causing the display panel to perform a display operation.
In a conventional liquid crystal display device, a plurality of semiconductor IC chips are mounted on a printed circuit board, and patterns of control signal wirings, power supply wirings, etc. which are used for controlling the timing at which the semiconductor IC chips are driven, are formed on the printed circuit board.
Recently, the number of semiconductor IC chips for driving liquid crystal display panels has been increasing in accordance with increases in the size of the display panels. The number of wirings used for signal transmissions between semiconductor IC chips mounted on a printed circuit board has been correspondingly increasing, which necessitates an increase in the size of the printed circuit board. However, the use of a large printed circuit board results in a large and heavy liquid crystal display device produced at high cost.
Moreover, in connection with an increase in the panel size, another requirement is to check the differences in the characteristics of a plurality of liquid crystal display panels, which may result from differences in the conditions, as well as to check electric characteristics such as signal delay in wirings when liquid crystal display panels are applied with liquid crystal driving voltages generated by liquid crystal driving IC chips. However, since a conventional liquid crystal display panel does not have wirings other than those for application of the driving voltages, the operation characteristics of the display panel cannot be externally monitored.
As mentioned above, a conventional liquid crystal display panel has the drawback that the operation characteristics of the display panel and electric characteristics such as signal delay in wirings cannot be externally monitored.
Further, a conventional liquid crystal display device is large in size, heavy, and high in cost, owing to an increase in the panel size.